1. Field of the Invention
One embodiment of the present invention relates to a semiconductor device. In particular, one embodiment of the present invention relates to a DC-DC converter and a semiconductor device using the DC-DC converter.
2. Description of the Related Art
A metal oxide having semiconductor characteristics called an oxide semiconductor has attracted attention as a novel semiconductor. A transistor using an oxide semiconductor is under development. For example, the structure of a DC-DC converter using the transistor is disclosed in Patent Document 1.